Indirection Explains Flexible Tuning of Neurons in Prefrontal Cortex

David Noelle, University of California, Merced

Abstract

The prefrontal cortex (PFC) is broadly seen as supporting
cognitive flexibility - quickly adapting behavior in response to changing
circumstances. Some PFC neurons appear to actively maintain rule-like information
associated with the current task, with firing changing with task context. Some
PFC neurons, however, have been found to exhibit activity related to specific
stimulus features or action options, but the tuning of these neurons appears to
dynamically change with task shifts (Duncan, 2001). Short-term synaptic
plasticity has been proposed as the primary mechanism for rapidly adapting the
response profiles of these cells. Using a computational cognitive neuroscience
model of hierarchical structure in PFC (Kriete, Noelle, Cohen, & O'Reilly, 2013),
an alternative account is offered in which flexible neural tuning arises not from
fast synaptic change but from a frontal representational scheme involving neurons
that encode references to other PFC areas rather than directly encoding task
relevant sensory/motor information.